RE: Slug gun help needed!!!
It's sad to say, but it's because they know people will buy them. If you read the add for Hornady's sabots they make them sound like they will shoot perfect out to 200 yards in any gun. Some don't know any better and buy them like hotcakes because it sounds so good.
And some guns do shoot them well, and there are several shotguns that have stock barrels with better twist rates as well. It's just the most common guns, H&R, Mossberg, and remington seem to still have the slower twists in them. At least in 12 ga models anyway. These guns were made to shoot the typical one ounce saboted lead slug. And be inexpensive to own and use. Retooling to keep up with the more modern shells would be very expensive I would guess.
That's my take on it anyway. And in my opinion why an inline muzzle loader still has the advantage over a slug gun, even with all the recent advancements in ammunition. If you were looking to shoot beyond 100 yards I would still look really hard at a quality inline and spend some range time dialing it in.
Paul